Once again Grant Rosewarne is skewing the facts. He says ["Yes or no to salmon farm growth", Express May 2] that "in terms of revenue per surface hectare, nothing can touch salmon farming".

Wrong, very wrong.

A land farmer growing stock utilises only the first 100 millimetres of the vertical part of his farm. A salmon farm may go down 30 metres or further.

Assuming that to be so, a salmon farm 50m long by 30m wide by 30m deep occupies 45,000 cubic metres of water space. Now, that alters the perspective and should be taken into account when comparing aquaculture with terraculture.

Using just the water surface measurements 50m by 30m we get an area of 1500 square metres, which is 0.666666 of a hectare and, on the face of it, is fantastic.

But, using the datum of 100mm of vertical space occupied by a land farm, and dividing the depth 30m by 100mm gives a figure of 300. If we now multiply the water surface area (1500m2) by 300 we arrive at a figure of 450,000 square metres, which is effectively 45 hectares.

That puts a different spin on the argument in favour of salmon farming, does it not? All in all, a fair dollop of water whichever way you look at it.

My argument is based on hypothetical dimensions for the fish farm, but through my observations of farms in the Sounds I think they are reasonable. However, the calculations are correct and only offered in support of my proposition.

DENIS WATERS

Picton

Shrimpton celebration

I am planning a 200th birthday party later in the year for my great-great grandfather, Ingram Shrimpton, and I'd like help to find my relatives.

The Shrimpton family played a significant part in the settlement of Canterbury and I would like to honour their memory with a gathering of descendants.

Ingram Shrimpton was the founder of the Lyttelton Times, the first newspaper in Canterbury. During his lifetime in New Zealand he also owned the Timaru Herald for a time and was a landowner in North Canterbury and South Canterbury.

Ingram and Jane Shrimpton had 12 children so the number of descendants must be considerable.

I invite any who read this to contact me via the Express with a view to joining the celebration, sharing information or just making contact.

This invitation includes descendants from Ingram's brother John and family, who came to New Zealand with them. Please email mailbox@marlexpress.co.nz or phone 035208906.

JOANNE GUMBRELL

Rangiora

Thanks, dad!

As I write this, there are only two sleeps left until the opening of both the duck hunting season and the first games of netball for junior players. My household are heavily involved in both; more on the netball a little later.

There are seven things you should never forget when you head outside with a firearm:

1. Treat every firearm as loaded.

2. Always point firearms in a safe direction.

3. Load a firearm only when ready to fire.

4. Identify your target beyond all doubt.

5. Check your firing zone.

6. Store firearms and ammunition safely.

7. Avoid alcohol and drugs when handling firearms.

So when you go out, enjoy yourself, be seen, be safe and we will all go home to our families afterwards.

As a side note, if you're not a fan of killing our feathered friends, I've just watched a story on the news where a butcher in a large supermarket chain was sacked for altering the use-by date on some products of meat. I think I'll stick to my game meats, thanks.

Now, if you had to be at the Blenheim netball courts by 10am on Saturday for the opening of the netball season, as we did, I ask who plans these things?

I hope you enjoyed yourselves, played hard, played fair, didn't talk back to the coach or umpire, were humble if you won and kept your chin up if you lost, and finally thanked your dad, who left his maimai at some ridiculous hour to get you to netball on time.

GRAEME RODGER

Rai Valley

Council spending

I have always believed that our council is charged with making judicious use of the hard-earned dollars gathered through our rates. One can't help but wonder where their priorities lie when a perfectly adequate traffic roundabout is dug up to be replaced and when a pocket park is planned despite negative public opinion.

Surely this money should be used for more deserving causes such as the repair of our war memorial.

Councils should listen to and serve their ratepayers – not just follow their own rigid plans.

RHONDDA TANNOCK

Blenheim

Engine brakes

Steve Murrin is quite correct when he says "engine brake signs make very little difference to the behaviour of truck drivers" ["Engine-brake signs wanted", Express, May 3]. Barry Blackley should be thankful he only has to put up with the engine brakes during harvest. It's a daily and nightly occurrence at Riverlands.

They start using their engine brakes at the "courtesy" sign and continue all the way round the Butter Factory corner. They clearly lack the driving skills needed to slow from 90kmh to 70kmh. Either that or they can't read.